A zones Delta-T can only be assessed once the system has been purged of the standing cold water within, and at least a single complete cycling of the water through the loop has occurred. What you are initially seeing is not Delta-T.hotblast1357 wrote: ↑Fri. Nov. 16, 2018 8:45 amCaught this just now, my downstairs radiator zone on a heat call, big delta T.
These temps are 10 degrees lower than actual, due to the probes being strapped on the black iron piping. So actual is 197/128.
For an example of this, the Taco VT-2218 Delta-T regulated circulator runs on its highest speed for 1 minute (or was it 2 minutes?) to purge the freshly calling zone of standing water, and only after that does it make its first Delta-T inquiry.